Oh yeah, there they are!

I use a home-made leather ammo wallet made by Kurt M_ years ago for his .475 N0.2. It is a better design than the ones pictured, and falls open when the press-stud is snapped. It carries 12 cartridges in two tiers of 6, all base-upwards when dropped open, 6-up and 6-down when closed. Its a good thing!